The Energy Balance Core is directed by Greg Morton, with Joshua Thaler serving as Associate Core Director. The primary function of this Core is to provide Affiliate Investigators (AIs) with state-of-the-art resources for comprehensive metabolic phenotyping of rodents. The Specific Aims for the Energy Balance Core are: Specific Aim 1: To provide AIs with a state-of-the-art resource for comprehensive energy balance and metabolic phenotyping of rodent models relevant to nutrition and obesity. The EB Core provides comprehensive quantitative assessment of energy balance parameters including indirect calorimetry with energy expenditure normalization by multiple linear regression, body and tissue composition on living and biopsied specimens, ambulatory activity, wheel running activity and energy intake with meal pattern analysis. We also offer video monitoring services and extensive thermoregulatory services including continuous core body temperature monitoring, calculation of thermal conductance, thermal gradient tests, and measures of brown adipose tissue and tail-temperature that can be performed at any ambient temperature using temperature- controlled chambers. As the EB Core is the sole provider of these services in the Seattle area, the UW NORC plays a critical role in the productivity and scientific advances of the nutrition and obesity research community. Specific Aim 2: To create an organizational structure that ensures that services are provided to AIs in a timely, efficient and cost-effective manner and that quality control for all services is routinely assessed. We optimize the scope of services offered and ensure that they fit seamlessly and without overlap with services offered via other UW programs and centers. To ensure services are provided to AIs in a timely and efficiency manner, the EB Core has implemented a streamlined process for animal transfers and handling; have highly skilled and trained personnel with extensive experience managing technically demanding equipment to ensure consistency and quality control; and strong leadership with expertise in the design, performance, analysis and interpretation of rodent metabolic phenotypes related to nutrition and obesity. Specific Aim 3: To develop new services that keep pace with relevant technological advances and address the evolving needs of our user base. Over the past 5 years, we have incorporated a number of innovative techniques into our expanded menu of offered services. We obtained a thermocline and temperature-controlled metabolic chambers for adaptive thermogenesis studies and introduced quantitative approaches to measure thermal conductance. In addition, we devote time and resources to teaching and training activities both to our NORC AIs and the broader scientific community, including normalization of energy expenditure data and the development of a seminar and workshop related to the regulation of energy homeostasis and use of indirect calorimetry equipment.